It has become no secret that a rise in the United States’ obesity epidemic, which has been associated with the increase in diabetes and heart disease prevalence, also coincided with dietary recommendations for a diet low in fat. Two recent studies published in the Annals of Internal Medicine have revealed that people looking to avoid obesity, cardiovascular disease, and diabetes should abandon low-fat dieting strategies for a diet that is low in carbohydrates.

Researchers involved with the study recruited 148 men and women who had not been diagnosed with cardiovascular disease or diabetes and randomly assigned them to one of two groups. Half of the participants were black and all were considered obese based on body mass index (BMI). The first group (low-carb group) was asked to adhere to a diet that permitted less than 40 grams of carbohydrates a day, while the second group (low-fat group) were asked to get less than 30 percent of their daily calories from fat.

The low-carb diet vs. low-fat diet debate, also known as the fat vs. sugar debate, has raged for some time now. Nutritional experts and dieticians tend to agree that the human body interprets and handles carbohydrates and sugar the same way. Sugar is often referred to as a simple or fast-acting carbohydrate. Low-carb diet advocates argue that a dieting plan that asks us to cut out fats also cuts out protein while increasing our intake of refined sugar and other unnatural ingredients.

After adhering to either a low-carb diet or a low-fat diet for one year, the research team analyzed each participant’s health using their weight, waist size, and blood tests. Weight loss in both groups was not attributed to exercise, since low-carb and low-fat group members participated in the same amount of physical activity. Members of the low-carb diet group lost an average of 7.7 pounds more than members of the low-fat diet group. Blood test results also revealed fats that are often attributed to a higher cardiovascular disease risk had decreased more in the low-carb diet group compared to the low-fat diet group.

In a separate study, researchers set out to determine obesity’s role in the upsurge of diabetes statistics since 1976 by examining data from five National Health and Nutrition Examination Surveys. The year 1976 also coincided with initial dietary recommendations advocating for a diet low in fat. The prevalence of diabetes nearly doubled between 1976 and 1980 as well as between 1999 and 2004. Among the three leading factors contributing to diabetes, including BMI, race/ethnicity, and age, an increase in BMI stood out during both time periods.

Source: Bazzano L, Hu T, Reynolds K, et al. Effects of Low-Carbohydrate and Low-Fat Diets. A Randomized Trial. Annals of Internal Medicine. 2014.